Elected officials and other groups representing those living below the troubled Oroville Dam have asked the Trump administration to hold off on renewing its 50-year license, saying the federal government should at least know why the spillway broke in half last winter before signing off.

On Wednesday, the dam’s owner, the California Department of Water Resources, sent a letter to the Federal Energy Regulatory Commission saying it was past time to renew the dam’s license, an effort that has been on hold for the past 11 years.

“All the environmental clearances, studies and other requirements have been meet,” DWR director Grant Davis wrote in the letter. “The last element needed is a majority vote of the commission.”

Northern Sacramento Valley groups and lawmakers, including Assemblyman James Gallagher, R-Yuba City, State Sen. Jim Nielsen, R-Tehama, and U.S. Rep. Doug LaMalfa, R-Richvale, argue that FERC should wait. They say a team of independent engineering consultants hired by DWR to determine a cause of February’s spillway failure hasn’t issued its final report on what went wrong. The north state groups say the findings could determine how the dam is operated in the coming decades.

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“We want to review the forensic report on why this happened,” Gallagher said Thursday morning on Twitter. “We want the impacts of the spillway crisis analyzed and mitigated, and we want to know how the (Oroville Dam) complex will operate long-term.”

Davis said in his letter that the troubles with the spillway and its ongoing $500 million repair job are separate from the dam’s hydroelectric license, which has been in limbo for more than a decade.

FERC requires hydroelectric dam owners to clear a slew of environmental and other regulatory hurdles before renewing a license.

As part of the relicensing, the state signed a settlement with the city of Oroville and nearly 50 other parties in 2006, promising to spend $1 billion on wildlife habitat and enhanced recreational facilities. The recreation component called for $438 million in new spending over 50 years, including additional RV campsites, more boat docks and picnic spots, and expanded parking along Lake Oroville. Most of that work is pending.

“DWR wants to follow through on its long standing commitment to make these improvements and investments – and can’t do that until the new license is issued,” said DWR spokeswoman Erin Mellon.

Federal fisheries agencies in charge of protecting salmon that spawn below the dam also needed to sign off. They finally gave their approval in 2016, but FERC couldn’t take action because it didn’t have enough people on its five-member board to approve the license. This summer, the U.S. Senate approved the Trump administration’s picks to filled the vacant seats, giving the board the ability to vote.

The urban and agricultural water contractors that store water behind Oroville Dam have already paid more than $60 million to get to this point in process, which has nothing to do with the spillway failure, said Jeff Kightlinger, general manager of the Metropolitan Water District of Southern California. Metropolitan is the largest of the State Water Contractors that pay for Oroville’s upkeep and maintenance.

“The relicensing is all about long term operations and 50-year impacts, and that was thoroughly studied,” he said.

But critics of the DWR and the water contractors say it’s important for the Trump administration to know why federal and state dam inspectors so badly missed clues that the spillway was about to fail before giving the state permission to run the dam for the next half century.

LaMalfa, the congressman whose family farms rice just outside the city of Oroville, said Thursday he wants the dam to be licensed as quickly as possible, but the spillway failure left too many unanswered questions.

“Was the failure because of design or maintenance? LaMalfa said. “What else about the dam and its maintenance should be taken into account? ... We’re not asking for a great big delay, especially in proportion to how long (the relicensing process) has taken already.”

State inspectors never sounded alarms about the spillway in their annual reports. FERC oversees an inspection every five years. FERC’s most recent inspection, conducted in late 2014, concluded that the a failure of the flood-control spillway at Oroville was so unlikely that there was no need to plan for such an emergency.

Oroville’s crisis began when a giant crater opened in the main spillway on Feb. 7. DWR officials throttled back water releases to limit the damage, but a heavy rainstorm filled Lake Oroville and water began spilling over the adjacent emergency spillway for the first time in the lake’s 48-year history. When it appeared the emergency spillway might fail, officials ordered the immediate evacuation of 188,000 downstream residents. DWR quickly ramped up releases over the main spillway, arresting the flow of water over the emergency structure, and lake levels fell.

The evacuation order was lifted two days later. The state hopes the Federal Emergency Management Agency will pay for the bulk of the repairs at the nation’s tallest dam. The water contractors will pay what’s left of the tab not picked up by federal taxpayers.

This compilation of drone footage from May 20, 2017 through November 1, 2017 highlights the transformation of Lake Oroville’s main spillway during repairs. Kiewit Infrastructure has led the massive construction effort to repair and reconstruct the McClatchyDepartment of Water Resources